Implement pagination for file entries in View class (#486)

* Implement pagination for file entries in View class

* Add resolveDirentFromListIndex method and refactor entry handling in View class

* Fix current_start_index calculation in View::update to prevent out-of-bounds access

Tactility/Private/Tactility/app/files/View.h

@@ -11,6 +11,10 @@ namespace tt::app::files {
 
 class View final {
     std::shared_ptr<State> state;
+    
+    size_t current_start_index = 0;
+    size_t last_loaded_index = 0;
+    const size_t MAX_BATCH = 50;
 
     lv_obj_t* dir_entry_list = nullptr;
     lv_obj_t* action_list = nullptr;
@@ -33,7 +37,7 @@ public:
     explicit View(const std::shared_ptr<State>& state) : state(state) {}
 
     void init(const AppContext& appContext, lv_obj_t* parent);
-    void update();
+    void update(size_t start_index = 0);
 
     void onNavigateUpPressed();
     void onDirEntryPressed(uint32_t index);
@@ -45,6 +49,10 @@ public:
     void onDirEntryListScrollBegin();
     void onResult(LaunchId launchId, Result result, std::unique_ptr<Bundle> bundle);
     void deinit(const AppContext& appContext);
+
+private:
+
+    bool resolveDirentFromListIndex(int32_t list_index, dirent& out_entry);
 };
 
 }